Speaker apparatus

Abstract

A speaker apparatus includes at least one of an inner flux applicator and an outer flux applicator includes an annular first member and an annular second member. The first member having a first surface that faces toward the magnetic gap, the first member satisfying L 1> W 1 where L 1 is a length of the first surface in a direction parallel to the central axis and W 1 is a width of the first member in a direction orthogonal to a central axis. The second member is magnetically coupled with the first member and arranged on an outer side of the first member, the second member satisfying W 2> L 2 where W 2 is a width of the second member in a direction orthogonal to a central axis and L 2 is a length of the second surface in a direction parallel to the central axis, and L 1> L 2.

1. A speaker apparatus comprising:
 a permanent magnet and a magnetic circuit, the magnetic circuit including an annular inner flux applicator and an annular outer flux applicator, the inner flux applicator and the outer flux applicator being arranged coaxially around a central axis and having a magnetic gap therebetween; 
 a voice coil arranged in the magnetic gap around the central axis, the voice coil being supported such that the voice coil can vibrate when the inner flux applicator and the outer flux applicator produce magnetic flux in the magnetic gap; and 
 a diaphragm coupled to the voice coil, the diaphragm being supported such that the diaphragm can vibrate when the voice coil vibrates, 
 wherein at least one of the inner flux applicator and the outer flux applicator includes
 an annular first member having a first surface that faces toward the magnetic gap, the first member satisfying L 1 >W 1  where L 1  is a length of the first surface in a direction parallel to the central axis and W 1  is a width of the first member in a direction orthogonal to a central axis; 
 an annular second member that is magnetically coupled with the first member and arranged on an outer side of the first member, the second member satisfying W 2 >L 2  where W 2  is a width of the second member in a direction orthogonal to a central axis and L 2  is a length of the second surface in a direction parallel to the central axis; and 
 
 L 1 >L 2 . 
 
     
     
       2. The speaker apparatus according to  claim 1 , wherein
 a first length of a part of the first member extending from the second member toward the diaphragm is shorter than a second length extending away from the diaphragm. 
 
     
     
       3. The speaker apparatus according to  claim 2 , wherein
 at least one of an extension of the first member extending axially from the second member toward the diaphragm and an extension extending from the second member away from the diaphragm is a cross-sectionally tapering section that gradually reduces in thickness towards an end thereof. 
 
     
     
       4. The speaker apparatus according to  claim 1 , wherein the first member and the second member have engaging sections that are mutually engaged to position the first member and the second member relative to each other. 
     
     
       5. The speaker apparatus according to  claim 4 , wherein
 the second member includes a disk with axially uniform thickness, and 
 the first member includes a cylindrical section with radially uniform thickness and an engaging section projecting from the side of the cylindrical section toward the second member to be engaged with the second member. 
 
     
     
       6. The speaker apparatus according to  claim 5 , wherein
 at least one of the engaging section of the first member and the second member has a cross-sectionally tapering section that gradually reduces in thickness outwards in the radial direction. 
 
     
     
       7. The speaker apparatus according to  claim 4 , wherein
 an outer diameter of the engaging section of the first member is smaller than an outer diameter is formed of the second member, whereby a step section is formed on a surface that is away from the permanent magnet, and 
 the heat radiator having a flexing circumferentially on the middle part in the radial direction and engages the step section formed by the engaging section of the first member and the second member. 
 
     
     
       8. The speaker apparatus according to  claim 7 , wherein
 the heat radiator has an inner part provided on an inner side of the flexion and in contact with the engaging section of the first member by surface and an outer part provided on an outer side of the flexion and in contact with the second member by surface, the outer part being fastened to the second member by a fastening unit penetrating orthogonally to the contact surface. 
 
     
     
       9. The speaker apparatus according to  claim 1 , wherein
 the first member is cylindrical; 
 the second member is disk-shaped; and 
 W 2 >W 1 . 
 
     
     
       10. The speaker apparatus according to  claim 1 , further comprising:
 a heat radiator made of a material with high thermal conductivity and thermally coupled with at least one of the first member and the second member. 
 
     
     
       11. The speaker apparatus according to  claim 10 , wherein
 the heat radiator functions as a securing member that secures the first member and the second member to each other. 
 
     
     
       12. The speaker apparatus according to  claim 10 , further comprising a frame that accommodates the magnetic circuit, wherein
 the heat radiator is supported by the frame and is also a securing member that secures at least the second member to the permanent magnet. 
 
     
     
       13. The speaker apparatus according to  claim 12 , wherein
 a peripheral edge of the heat radiator is thermally coupled with the frame. 
 
     
     
       14. The speaker apparatus according to  claim 13 , wherein
 the peripheral edge has a frame contact section extendingly formed so as to expand along an inner surface of the frame. 
 
     
     
       15. The speaker apparatus according to  claim 13 , further comprising:
 an engaging step section, on the inner surface of the frame, that engages a peripheral edge of the heat radiator. 
 
     
     
       16. The speaker apparatus according to  claim 12 , further comprising:
 an opening on the frame to allow flow of air in the frame from outside. 
 
     
     
       17. The speaker apparatus according to  claim 10 , wherein
 the heat radiator has vents formed through the heat radiator to allow passage of air in the heat radiator from outside. 
 
     
     
       18. The speaker apparatus according to  claim 1 , wherein
 the inner flux applicator has a long columnar shape, the permanent magnet has an annular shape and is coaxially arranged around the inner flux applicator, and the outer flux applicator coaxially arranged around the inner flux applicator, and the magnetic gap is formed between an outer surface of the inner flux applicator and an inner surface of the outer flux applicator. 
 
     
     
       19. The speaker apparatus according to  claim 18 , further comprising a frame configured to accommodate the inner flux applicator, the permanent magnet, and the outer flux applicator, the inner flux applicator having a radial extension that radially extends from a base end, wherein
 the radial extension is thermally connected to the frame. 
 
     
     
       20. The speaker apparatus according to  claim 1 , wherein
 the permanent magnet is columnar, the inner flux applicator is overlaid on the permanent magnet, and the outer flux applicator is cylindrical and coaxially provided around the inner flux applicator, and the magnetic gap is formed between an outer surface of the inner flux applicator and an inner surface of the outer flux applicator.